As used herein, it wilt be understood that the terms outer race and cup (102) are used interchangeably.
The present invention relates generally to bearings and, in particular to a bearing assembly configured with sensors to monitor applied forces and torques to provide responsive signals for use by devices, which monitor the bearing loads.
The bearing assembly of the present invention may be used to measure radial forces, thrust force, tilting moments, rotation speeds, and temperature at the bearing for use in many applications such as Vehicle Dynamics Control Systems (Vehicle Stability Control Systems), vehicle rollover prevention systems, tire-integrity monitoring systems, road-condition monitoring systems, and vehicle suspension-control systems.
There are a number of applications where the loads and types of loads placed on a bearing assembly in operation can provide significant information about the bearing and the objects attached to the bearing assembly. For example, in the automotive industry, bearing loading information, in electrical signal form, is utilized by a Vehicle Dynamics Control (“VDC”) Systems to monitor the driving conditions of the vehicle, enabling the system to control the torque supplied to the vehicle wheels. An antifriction rolling bearing disclosed in U.S. Pat. No. 5,140,849 to Fujita et al. uses two strain gages to monitor the general loads applied to a bearing. However, the '849 Fujita et al. bearing assembly is unable to provide the multi-faceted data needed by high-level VDC electronic systems or by the processor-controlled systems in the rolling-mills industry or the machine-tool industry.
U.S. Pat. No. 4,748,844 to Yoshikawa et al. discloses a load-detection device related to the automotive industry, consisting of a multi-component load cell structure fixed to a hub on which a road wheel is mounted. The load cell structure is attached so as to rotate with the tire of the wheel. However, the device disclosed in the '844 Yoshikawa et al. patent cannot provide signals indicating all loads and all torques required to enable a high level VDC electronic device or other such monitoring devices to function properly. In particular, the device employs strain gages in only one plane, perpendicular to the axis about which the wheel rotates. As a result, the signals from the strain gages on the device are unable to detect the forces tending to cause a vehicle to skid sideways or to roll the vehicle over.
In the steel production industry, steel rolling mills utilize electronic processing and control to manipulate the speed and loads associated with rollers during a steel rolling process. Specifically, rolling mills need bearing feedback regarding indications of a belt slipping on rollers or indications that a particular set of rollers is experiencing higher loads and torques.
Similarly, in the machine tool industry, programmable controllers and processors monitor and control the speed and loads associated with spindles in a variety of milling, cutting, and drilling machines. Computer controlled machine tools monitor the amount of force and torque being experienced by bearings supporting a spindle in order to assess whether cutting and drilling tools have become dull or whether the cutting or drilling force, torque, and speeds exceed the limits established for proper machining operations.
Corresponding reference numerals indicate corresponding parts throughout the several figures of the drawings.